Frog skin could thwart antibiotic-resistant germs

The skin of certain frogs, including this foothill yellow-legged frog, contain secretions that may lead to new antibiotics to fight infections that shrug off the effects of existing antibiotics. (Photo: Pierre Fidenci, CC)

While kissing a frog might not transform him into a handsome prince, his skin might one day save your life. Scientists in Abu Dhabi have discovered a method for using the natural substances found in frog skins to create a powerful new group of antibiotics with potential to fight against drug-resistant infections.

At the 240th National Meeting of the American Chemical Society, the team of researchers led by Dr. Michael Conlon, a biochemist at the United Arab Emirates University in Al-Ain, Abu Dhabi Emirate, explained how they have identified more than 100 antibiotic substances in the skins of different frog species from around the world. He also highlighted how one of the hundred has the ability to fight "Iraqibacter," the bacterium responsible for drug-resistant infections in wounded soldiers returning from Iraq.

Dr. Conlon went on to explain how the emergence of drug-resistant bacteria, which generally shrug off conventional antibiotics, is a growing concern worldwide. Thus there is a need to create new drugs to replace the types of antibiotics that no longer work.

"Frog skin is an excellent potential source of such antibiotic agents," said Conlon. “They've been around 300 million years, so they've had plenty of time to learn how to defend themselves against disease-causing microbes in the environment. Their own environment includes polluted waterways where strong defenses against pathogens are a must."

It has been known for many years that the frog’s skin is a rich source of chemicals with the potential to fight against many forms of bacteria, viruses and fungi. However the problem has been the fact the frog antibiotics tend to be toxic to human cells. Dr. Conlon and team have created a new technique which tweaks the molecular structure of frog skin antibiotic substances, resulting in a powerful germ killer that is less toxic to human cells. The frog secretions can be altered to resist attack by destructive enzymes in the bloodstream and become powerful, long lasting antibiotics. Dr. Conlon went on to explain how the frog antibiotics work in an unusual manner, preventing disease-causing microbes from developing a resistance.

Currently the scientists are screening skin secretions from more than 6,000 species of frogs, specifically for antibiotic research. To date they have discovered the chemical structure of close to 200, leaving room for many more antibiotic substances to be determined. "Many people are working with me, giving me samples of frog skin secretions," said Dr. Conlon, who in addition to his team in Abu Dhabi has several research collaborators in Japan, France, the United States, amongst other countries. "We only actually use the frogs to get the chemical structure of the antibiotic, and then we make it in the lab. We take great care not to harm these delicate creatures, and scientists return them to the wild after swabbing their skin for the precious secretions" added Dr. Conlon.

One exciting discovery came from the skin secretions of the Foothill Yellow-Legged Frog, a species found in California and Oregon which is now facing extinction. This secretion illustrated promise for fighting Methicillin-Resistant Staphylococcus Aureus (MRSA) bacteria. MRSA is a "superbug" often responsible for causing fatal infections within hospitalized patients, schools, nursing homes and day care centers. In addition, as previously mentioned, the skin of the Mink Frog contains secretions that may fight "Iraqibacter," caused by multidrug-resistant Acinetobacter Baumanni.

Dr. Conlon is hoping that some of the antibiotics could be used in clinical trial within the coming years. Amongst creating powerful vaccines and treatments for drug-resistant infections throughout the body, the secretions could also be used in ointments to treat simple skin infections.

The skin of certain frogs, including this foothill yellow-legged frog, contain secretions that may lead to new antibiotics to fight infections that shrug off the effects of existing antibiotics. (Photo: Pierre Fidenci, CC)